PROJECT SUMMARY/ABSTRACT Adolescents (ages 10-19) experience disproportionately low retention, antiretroviral (ART) adherence and viral suppression compared to other age groups. HIV care programs in high prevalence, resource-limited settings have developed innovative approaches to improve linkage, retention and viral suppression, including simplified treatment regimens, task-shifting, and peer support. However, clear policies and practices for enrolling adolescents in HIV services and research, as well as systematic strategies that identify adolescents who need more intensive care to successfully achieve key milestones along the HIV care continuum, are lacking. ?Stepped care? approaches, where the most at-risk clients receive increasing levels of intensity and frequency of care, have been used to target interventions and efficiently use resources. A clinical prediction tool using standardized risk scores can help healthcare providers to identify adolescents at greater risk of experiencing negative outcomes and direct interventional support to them. Our data-informed stepped care (DiSC) intervention pairs stepped care with a clinical prediction tool to optimize limited resources and improve HIV care and treatment outcomes. Our team, which has worked with pediatric and adult HIV programs in Kenya for over two decades, including an established repertoire of adolescent HIV studies, proposes to implement this combination data- driven intervention using a stepped care model to inform public health decision-making and improve adolescent HIV care in Kenya. Formative work in UG3 will include establishment of a clinic-based prospect cohort of adolescents ages 10-19 and their care givers at 6 high volume HIV clinics in Western Kenya. Based on data derived from surveys and abstraction of electronic medical records, we will determine key predictors of loss to care and suspected virologic failure, and develop a clinical prediction tool to identify adolescents needing more intensive support. We will conduct focus groups and interviews to understand and optimize adolescent consent and representative participation in HIV care and research. This work, including adolescent and community stakeholder perspectives, will inform development and optimization of the DiSC intervention for adolescent HIV treatment management in UH3. DiSC will be evaluated through a cluster randomized trial at 20 high-volume HIV clinics, looking at both effectiveness (6 and 12-month retention, viral suppression, ART adherence) and implementation outcomes (feasibility and acceptability). These aims have potential to provide a generalizable, systematic approach to deliver differentiated adolescent HIV care that integrates with diverse HIV care programs and available support options to accelerate progress toward achieving the 90-90-90 targets for adolescents.